JP2005079336A - Heat treatment apparatus, heat treatment method and method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment apparatus and a heat treatment method, in which a desired temperature distribution can be obtained in all regions of the treating substrate of a large area at a low cost. <P>SOLUTION: The heat treatment apparatus comprises a treatment chamber 2 for containing a treating substrate 1, a plurality of bar-like lamps Q<SB>i</SB>(i=1 to n) which are disposed (laid out) at an identical pitch in a constant direction for irradiating ultraviolet lights on the treating substrate 1, respectively, detectors D<SB>ij</SB>(i=1 to n; j=1 to m) for receiving the ultraviolet lights of the bar-like lamps Q<SB>i</SB>via the treating substrate 1, respectively, and a control circuit 4 which feeds back the voltage value of light intensity to a power supply voltage based on a distribution of the light intensity, to independently and simultaneously control outputs of the bar-like lamps Q<SB>i</SB>, respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat treatment apparatus, and more particularly, to a lamp heating type heat treatment apparatus, a heat treatment method, and a semiconductor device manufacturing method using the same.

  In a manufacturing process of a polycrystalline silicon thin film transistor (TFT) used in a liquid crystal display (LCD) or the like, amorphous silicon (a-Si) is formed on a glass substrate and irradiated with an excimer laser to increase a-Si. An excimer laser annealing (ELA) method for crystallizing is known.

  In the ELA method, a laser beam shaped into a linear shape of several hundred mm in the major axis direction and several hundred μm in the minor axis direction is scanned and irradiated on the substrate at a repetition frequency of about 300 Hz. Assuming that the substrate size and the overlap during irradiation are constant, the processing time for polycrystallizing a-Si depends on the laser output and the repetition frequency. For example, when a glass substrate of 550 × 650 mm is irradiated with a shaping beam having a major axis of 275 mm and a minor axis of 0.4 mm with an overlap rate of 10% (overlapping number of 10 shots), 32000 is used to irradiate the entire substrate. About a shot is required, and the time required for irradiation is about 110 seconds.

In recent years, lamp annealing apparatuses using a plurality of rod-shaped lamps have been proposed as means for polycrystallizing a-Si (see, for example, Patent Documents 1 and 2).
JP 2001-24476 A JP 2000-30594 A

  However, conventionally, a temperature control technique in a heat treatment apparatus and a heat treatment method in which several or more rod-shaped lamps are turned on simultaneously and the entire surface is irradiated at a time has not been developed.

  In particular, there is a need for a heat treatment apparatus and a heat treatment method that simultaneously turn on a plurality of rod-shaped lamps and uniformly irradiate a large-area glass substrate with a light intensity distribution to obtain a uniform temperature distribution.

  In view of the above problems, an object of the present invention is to provide a low-cost heat treatment apparatus and heat treatment method that can obtain a desired temperature distribution over the entire area of a substrate to be processed having a large area. To do.

  Another object of the present invention is to provide a semiconductor device manufacturing method capable of realizing a high-quality semiconductor thin film at a low cost and in a short time with a large area and high in-plane uniformity.

  In order to achieve the above object, the first feature of the present invention is: (a) a processing chamber having a window portion having a good ultraviolet-transmitting property and containing a substrate to be processed; (b) outside the processing chamber in a certain direction. A plurality of rod-shaped lamps arranged at the same pitch and heating the substrate to be treated with light having an emission spectrum including ultraviolet rays through the window; (c) the light of the plurality of rod-shaped lamps is treated independently. A plurality of detectors arranged opposite to the array of the plurality of rod-shaped lamps so as to receive light through the substrate; (d) a plurality of detectors based on the distribution of light intensity measured by the plurality of detectors; The main point is that the heat treatment apparatus includes a control circuit unit that simultaneously and independently controls the outputs of the bar lamps.

The second feature of the present invention is summarized as a heat treatment method including the following steps:
(A) placing the substrate to be processed inside the processing chamber;
(B) The emission spectrum including ultraviolet rays from a plurality of rod-shaped lamps arranged at the same pitch in a fixed direction outside the processing chamber through a window portion having a good ultraviolet transmission property provided in a part of the processing chamber. Introducing light and heating the substrate to be processed;
(C) a step of independently measuring the light intensities of the light from the plurality of rod-shaped lamps through the substrate to be processed;
(D) A step of independently controlling the outputs of the plurality of rod-shaped lamps based on the measured light intensity.

The gist of the third feature of the present invention is a method for manufacturing a semiconductor device, which includes the following steps and processes at least a part of the semiconductor thin film or forms a new film on the surface of the semiconductor thin film:
(B) a step of installing a substrate to be processed having a semiconductor thin film formed on at least the surface; and (b) a plurality of rods arranged at the same pitch in a fixed direction at a position facing the semiconductor thin film formed on the substrate to be processed. Introducing light of an emission spectrum including ultraviolet light from a lamp into a semiconductor thin film and heating a substrate to be processed;
(C) a step of independently measuring the light intensities of the light from the plurality of rod-shaped lamps through the substrate to be processed;
(D) A step of independently controlling the outputs of the plurality of rod-shaped lamps based on the measured light intensity.

  According to the present invention, a desired temperature distribution can be obtained over the entire region of a large substrate to be processed, and a low-cost heat treatment apparatus and heat treatment method can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the semiconductor device which can implement | achieve a high-quality semiconductor thin film at a low cost for a short time can be provided with a large area and high in-plane uniformity.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the following embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, The layout is not specified as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

<Heat treatment equipment>
As shown in FIG. 1, the heat treatment apparatus according to the embodiment of the present invention is arranged (arranged) at the same pitch in a fixed direction above the processing chamber 2 for storing the substrate 1 to be processed and the processing chamber 2. a plurality of rod-shaped lamps Q _i (i = 1 to n, n is an integer of 2 or more.) and, parallel the position of the center axes of the rod-shaped lamp Q _i in a direction perpendicular to the array surface of the plurality of rod-shaped lamps Q _i projection Of the light intensity measured by the plurality of detectors D _ij (i = 1 to n, j = 1 to m; n and m are integers of 2 or more) and the plurality of detectors D _ij . And a control circuit unit 4 for controlling the outputs of the plurality of rod-shaped lamps Q _i based on the distribution. As shown in FIG. 1, the plurality of rod-shaped lamps Q _i are disposed above the processing chamber 2 in parallel with each other and apart from each other. The control circuit unit 4 is connected to a plurality of bar lamps Q _i and a plurality of detectors D _ij .

A plurality of detectors D _ij are arranged along a position _where the central axes of the respective rod lamps Q ₁ , Q ₂ ,..., Q _n are projected in parallel, and constitute a matrix as a whole. . For example, as shown in FIG. 2, along the central axis of the rod-shaped lamp Q _1, the detector _{D 11, D 12, ·····,} D 1m a plurality, are arranged one-dimensionally, the rod-shaped lamp Q ₂ A plurality of detectors D ₂₁ , D ₂₂ ,..., D _2m are arranged one-dimensionally along the central axis. Furthermore, a plurality of detectors D _n1 , D _n2 ,..., D _nm are arranged one-dimensionally along the central axis of the rod-shaped lamp Q _n .

  The processing chamber 2 has a gas introduction port 22, a gas exhaust port 23, and a window 24 with good ultraviolet transmission characteristics. The window 24 corresponds to the “window portion having a good ultraviolet transmission characteristic” of the present invention. As will be described later with reference to FIG. 11, the processing chamber 2 itself is made of a material having a good ultraviolet transmission characteristic. It is needless to say that the portion may have a function of “a window portion having good ultraviolet ray transmission characteristics”.

The gas introduction port 22 is arranged, for example, on the left side surface of the processing chamber 2 so that the processing gas can be introduced into the processing chamber 2. Examples of the processing gas include an inert gas such as nitrogen (N ₂ ) gas, argon (Ar) gas, helium (He) gas, or a mixed gas of any of these inert gases and oxygen (O ₂ ). Etc. can be used. However, hydrogen (H ₂ ) gas, silicon tetrachloride (SiCl ₄ ), trichlorosilane (SiHCl ₃ ), dichlorosilane (SiH ₂ Cl ₂ ), an organic metal compound, or the like, depending on the content of the processing performed in the processing chamber 2. Various gases such as gas can be used as the processing gas. The gas exhaust port 23 is disposed on the right side opposite to the left side where the gas introduction port is disposed. Control of the flow rate and partial pressure of the processing gas in the processing chamber 2 can be adjusted by valves (not shown) provided in the gas introduction port 22 and the gas exhaust port 23. In order to adjust the gas flow rate, a flow rate adjusting valve such as a mass flow controller may be provided only on the gas introduction port 22 side. The window 24 is disposed on the upper surface of the processing chamber 2, and quartz glass, sapphire glass, or the like can be used as a material having good ultraviolet transmission characteristics.

Furthermore, a stage 21 is provided on the bottom surface of the processing chamber 2 to fix the substrate 1 having a large area on the top surface. Although not shown, the stage 21 may include a heater (resistance heating device) that can be heated to increase the reactivity of the substrate 1 to be processed. In FIG. 1, the substrate 1 to be processed is one in which an amorphous semiconductor film (a-Si film) 1 d is formed on the upper surface of the transparent substrate 1 a, but is not limited thereto. The stage 21 is movable in the horizontal direction (the left-right direction toward the paper surface of FIG. 1) inside the processing chamber 2. As shown in FIGS. 1 and 2, the stage 21 is provided with a plurality of pinholes H _ij (i = 1 to n, j = 1 to m; n and m are integers of 2 or more) periodically. ing. The plurality of pinholes H _ij are arranged in the upper part corresponding to the positions of the plurality of detectors D _ij . The specific size of the pinhole H _ij may be 0.05 mm to 0.3 mm, more preferably about 0.08 mm to 0.15 mm, for example, about 0.1 mm, but is not limited thereto. The size of the pinhole H _ij may be determined by comprehensively considering the output of the rod lamps Q ₁ , Q ₂ ,..., Q _n and the sensitivity of the detector D _ij . In any case, a plurality of pinholes H _ij are arranged along the positions _where the central axes of the respective rod lamps Q ₁ , Q ₂ ,..., Q _n are projected in parallel, and a matrix is formed as a whole. It is composed. That is, as shown in FIG. 2, along the central axis of the rod-shaped lamp Q _1, pinhole _{H 11, H 12, ·····,} H 1m are arranged a plurality, in linear, rod-shaped lamp Q ₂ A plurality of pinholes H ₂₁ , H ₂₂ ,..., H _2m are arranged along the central axis. Further, a plurality of pinholes H _n1 , H _n2 ,..., H _nm are arranged along the central axis of the rod-shaped lamp Q _n .

A detector D _ij disposed below the plurality of pinholes H _ij receives the light from the rod-shaped lamp Q _i through the substrate 1 and the pinholes H _ij and measures the light intensity. As the detector D _ij , in addition to a photodiode, lead zirconate titanate (PZT), lithium tantalate (L _i TaO ₃ ), glycine sulfate (TGS), polyvinylidene fluoride (PVF ₂ ), titanate A pyroelectric detector such as lead (PbTiO ₃ ) can be used. In view of the magnitude of the light emission output of the rod-shaped lamp Q _i and the optical filter characteristics of the substrate 1 to be processed, a pyroelectric detector capable of measuring a large output without wavelength dependence is preferable. The pyroelectric detector can detect the temperature of the substrate 1 as heat rays (infrared rays).

The rod-shaped lamp Q _i is a straight tube type flash lamp. In order to make the energy of light irradiated to the substrate 1 to be processed uniform, this straight tube flash lamp may use, for example, a deformed tube having a narrow diameter at both ends and a large diameter at the center. For the purpose of heat-treating the a-Si film 1d formed on the upper surface of the transparent substrate 1a as shown in FIG. 1 to be polycrystallized, an ultraviolet lamp having an emission spectrum as shown in FIG. 3 is preferable. In FIG. 3, the wavelength integrated value Ia of the light intensity I in the wavelength region of wavelength 400 nm or less is 20% or more with respect to the wavelength integrated value Ib of the light intensity I in wavelength region of 400 nm or more.

  As the ultraviolet lamp having an emission spectrum as shown in FIG. 3, for example, a xenon (Xe) flash lamp or a Xe flash lamp containing a trace amount of metal halide or mercury (Hg) is preferable. In particular, it is preferable to use a mercury xenon (Hg-Xe) flash lamp in which a very small amount of mercury is enclosed as a rod-shaped lamp that is low in cost and can obtain a high current density as compared with a discharge part of an excimer laser. The bulb of the ultraviolet flash lamp is preferably one having good ultraviolet transmission characteristics such as quartz glass or sapphire glass, but hard glass may be used.

As shown in FIG. 4, the amount of light emitted at a wavelength of 400 nm or less included in the Hg-Xe flash lamp increases as the amount of Hg increases. For this reason, as the rod-shaped lamp Q _i for the purpose of polycrystallizing the a-Si film 1d, an Hg-Xe flash lamp having a high mercury content, preferably an Hg-Xe flash lamp having a mercury content of 0.1 mg / cc or more. It is good to use. Instead of Xe, a krypton (Kr) rod flash lamp may be used.

The heat treatment apparatus according to the embodiment of the present invention has a plurality of reflecting mirrors M _i (i = 1 to n, where n is an integer of 2 or more) disposed above the plurality of rod-shaped lamps Q _i shown in FIG. It has further. A plurality of reflecting mirrors M _i is the direction of the substrate 1 to respectively reflect the light emitted in different directions, it is irradiated in the direction of the substrate 1. Each of the plurality of reflecting mirrors M _i, a parabolic, irradiated by reflected light of a plurality of rod-shaped lamps Q _i in the direction of the substrate 1. Each of the plurality of reflecting mirrors M _i has a function of making the illuminance uniform, and parallel light can be obtained by arranging the rod-shaped lamps Q _i at the focal position of the parabolic mirror. Note that a certain object can be achieved by using, for example, a spherical mirror or a plane mirror instead of the parabolic mirror.

As shown in FIG. 5, a plurality of power supply circuits X _i (i = 1 to n, where n is an integer of 2 or more) are connected between the plurality of rod lamps Q _i and the control circuit unit 4. Yes. The plurality of power supply circuits X _i supply current to the plurality of bar lamps Q _i , respectively. Further, the control circuit unit 4 includes a central processing control device (CPU) 41, a stage driving device 42 connected to the CPU 41, a plurality of detectors D _ij , a plurality of power supply circuits X _i and a plurality of CPUs 41 connected to the CPU 41, respectively. Comparison calculator Y _i (i = 1 to n, n is an integer of 2 or more), a current measuring device 44 connected to the CPU 41, a plurality of power supply circuits X _i and a voltage controller 45 connected to the CPU 41. And have.

The CPU 41 controls the stage driving device 42, the plurality of comparison calculators Y _i , the current measuring device 44, and the voltage controller 45, respectively. In order to make the light intensity distribution uniform, the stage driving device 42 slides the stage 21 in the horizontal direction so as to irradiate the light from the plurality of rod-shaped lamps Q _i while overlapping the irradiation point positions. The plurality of comparison calculators Y _i compare the light intensity distribution measured by the plurality of detectors D _i1 , D _i2 ,..., D _im below the plurality of bar lamps Q _i with a reference value. To do. The current measuring device 44 measures the peak value and half value of the current supplied to each of the plurality of rod-shaped lamps Q _i . The voltage controller 45 finely adjusts the power supply voltages of the plurality of power supply circuits X _i so that the peak value of the current becomes constant.

Here, i = 1 to n (n is an integer of 2 or more), and measured by a plurality of detectors D _i1 , D _i2 ,..., D _im below the plurality of bar lamps Q _i . If the light intensities to be obtained are I _i1 , I _i2 ,..., I _im , the average value I _{i of the} light intensities is obtained from equation (1):
(I _i1 + I _i2 + ... + I _im ) / m = I _i (1)
The control circuit unit 4 compares the distribution of the light intensities I _i1 , I _i2 ,..., I _im with a reference value by each of the plurality of comparison calculators Y _i . According to this comparison, when the average value I _i of the light intensity is lower than the reference value, the voltage value of the average value I _i of the light intensity is fed back to the power supply voltage of each power supply circuit X _i . For example, the voltage value of the power supply voltage is increased by 100 V, and the outputs of the plurality of bar lamps Q _i are controlled. A plurality of current probes B _i (i = 1 to n, n is an integer of 2 or more) are connected to the current measuring device 44. The current measuring device 44 measures the peak value and half value of the current supplied to the plurality of rod-shaped lamps Q _i through the plurality of current probes B _i . Note that the display device 100 may be connected to the CPU 41 so that the light intensity distribution and the like can be displayed. In this case, the CPU 41 controls the input of light intensity information and the like to the display device 100.

As a discharge circuit that outputs the light of each of the plurality of rod-shaped lamps Q _i , for example, as shown in FIG. 6, a rod-shaped lamp Q _i and a power supply circuit X _i connected to the rod-shaped lamp Q _i may be provided. Further, each of the plurality of rod-shaped lamps Q _i includes a discharge unit 32 and a trigger circuit 33 connected to the discharge unit 32. The discharge part 32 is connected to the ground potential V _SS via the terminal 31a. Further, the discharge unit 32 is connected to a plurality of power supply circuits X _i through the terminal 31b.

Further, each of the plurality of power supply circuits X _i includes a DC power supply 62, a power switch 63 connected to the DC power supply 62, an inverse L-type circuit 64 connected to the power switch 63, and a power switch 63 and an inverse L-type. A resistor R ₁ connected to a node P ₁ between the circuit 64 and a diode 65 whose output side is connected to the resistor R ₁ is provided. The DC power source 62 is connected to the ground potential V _SS via the terminal 61a. The diode 65 is connected to the ground potential V _SS via the terminal 61b. The inverted L-type circuit 64 is connected to the ground potential V _SS via the terminal 61c. The inverted L-type circuit 64 is connected to the rod-shaped lamp Q _i through the terminal 61d. Further, the inverted L-type circuit 64 includes a resistor R ₂ connected to the power switch 63 and a capacitor 66 connected to a node P ₂ between the resistor R ₂ and the terminal 61 d. The capacitor 66 is connected to the ground potential V _SS via the terminal 61c. In addition, the peak value and the half value of the current supplied to the rod-shaped lamp Q _i are measured by the current measuring device 44 through the plurality of current probes B _i .

  In the discharge circuit shown in FIG. 6, first, the power switch 63 is closed, and the charge from the DC power supply 62 is accumulated in the capacitor 66 of the inverted L-type circuit 64. Next, when the power switch 63 is opened and a signal such as a pulse wave is emitted from the trigger circuit 33, the electric charge accumulated in the capacitor 66 moves to the discharge part 32, and pulsed ultraviolet light is generated transiently. To do.

<Heat treatment method>
(A) In the heat treatment apparatus according to the embodiment of the present invention, first, the plurality of rod-shaped lamps Q _i are aligned in an unloaded state where the substrate 1 to be processed is not placed on the stage 21. As shown in FIG. 2, a plurality of detectors D ₁₁ , D ₁₂ ,..., D _1m are arranged one-dimensionally along the central axis of the rod-shaped lamp Q ₁ , and the central axis of the rod-shaped lamp Q ₂ is arranged. along the detector _{D 21, D 22, ·····,} D 2m a plurality, ..., along the central axis of the rod-shaped lamp Q _n, the detector D _n1, D _n2, · .... since D _nm a plurality are arranged one-dimensionally, firstly, for each of the rod-shaped lamp Q _i, the detector D _i1, D _i2, · · · · ·, the light measured by the D _im Each of the rod-shaped lamps Q _i is aligned so that the intensity is constant. Therefore, as shown in FIG. 2, the stage 21 shown in FIG. 1 has a gonio function capable of rotating with respect to a rotation axis perpendicular to the axial direction of the plurality of rod-shaped lamps Q _i . In order to center the rod-shaped lamp Q _i , the number of one-dimensional arrays m ≧ 3 is preferable. If the number of one-dimensional arrays m = 3, each of the rod-shaped lamps Q _i can be aligned so that the light intensity at the center and both ends is constant. Further, in FIG. 2, if a plurality of bar lamps are used in the vertical direction, the number m of the one-dimensional array can be selected to be a multiple of 3 according to the number of bar lamps arranged in the vertical direction. preferable. On the other hand, as shown in FIG. 6, the current waveform of the discharge current of each rod-shaped lamp Q _i is monitored with an oscilloscope or the like using a current probe B _i . The peak value of the current waveform measured by the current probe B _i is fed back, and the power supply voltages of the plurality of power supply circuits X _i are finely adjusted independently. For the purpose of obtaining a uniform temperature distribution, in general, the power supply voltage of each of the plurality of power supply circuits X _i may be finely adjusted so that the peak value of the current waveform is constant.

(B) Next, the substrate 1 to be processed is placed on the stage 21 and fixed on the stage 21. Then, a plurality of detectors D _21, D _22, ·····, in D _2m, monitoring the intensity changes during annealing of the respective bar-shaped lamp Q _i, adjusting the input energy to each of the rod-shaped lamp Q _i To do. That is, when ultraviolet light from a plurality of rod-shaped lamps Q _i is irradiated onto the substrate 1 as shown in FIG. 7, the plurality of detectors D _ij process the light from the plurality of rod-shaped lamps Q _i. Light intensity I _ij is measured by receiving light through the substrate 1 and the pinholes H _i1 , H _i2 ,..., H _im shown in FIG. When a pyroelectric detector is used as each of the plurality of detectors D _ij , the pyroelectric detector uses the substrate 1 to be processed as an optical filter, and the substrate 1 to be processed is included in the emission spectrum of the rod-shaped lamp Q _i. The light component that passes through the substrate and the thermal energy generated by heating the substrate 1 to be processed are simultaneously detected. Each comparison operation unit Y _i of the control circuit unit 4 obtains an average value I _i of the measured light intensities I _i1 , I _i2 ,..., I _im as shown in Expression (1). Each light intensity average value I _i shown in Expression (1) is compared with a reference value in each comparison calculator Y _i . The control circuit unit 4 controls the voltage value of the DC power supply 62 of the corresponding power supply circuit X _p, to control the output of the corresponding rod-shaped lamp Q _p independently. If the purpose is to obtain a uniform temperature distribution, the control circuit unit 4 determines that the DC power supply 62 of the corresponding power supply circuit X _p when the light intensity average value I _p of the specific rod-shaped lamp Q _p is lower than the reference value. constant voltage step a voltage value of, for example, is raised by 100 V, to increase the output of the corresponding rod-shaped lamp Q _p. Conversely, when the average light intensity value I _q of a specific bar lamp Q _q is lower than the reference value, the voltage value of the DC power source 62 of the corresponding power circuit X _q is decreased in a constant voltage step, and the corresponding bar lamp Q _Reduce the output of _q . It is possible not only to make the outputs of all the rod-shaped lamps Q _q uniform, but also to adjust so that only the outputs at both ends of the array of the plurality of rod-shaped lamps Q _i are increased. In any case, a desired temperature distribution can be obtained by feeding back the light intensity measured by the plurality of detectors D _i1 , D _i2 ,..., D _im to each power supply circuit X _i in this way. It becomes possible to obtain.

(C) At this time, the peak value of the current waveform measured by the current probe B _i is fed back, and the power supply voltages of the plurality of power supply circuits X _i are finely adjusted independently. For the purpose of obtaining a uniform temperature distribution, the power supply voltage of each power supply circuit X _i is adjusted so that the peak current value becomes constant. That is, the current measuring device 44 shown in FIG. 3 measures the peak value and half value of the current supplied to each rod-shaped lamp Q _i through the plurality of current probes B _i , and the voltage controller 45 measures the current peak value. The power supply voltage of each power supply circuit X _i is finely adjusted so that becomes constant.

According to the heat treatment apparatus according to the embodiment of the present invention, the control circuit unit 4, a plurality of detectors D _i1, D _i2, · · · · ·, the light intensity is measured by D _im I _i1, I _i2, ..., based on the average value I _i of I _im, by feeding back the average value I _i of the light intensity as a voltage value to the power supply voltage of the power supply circuits X _i, the output of each of the rod-shaped lamp Q _i, respectively Can be controlled. Further, the voltage controller 45 can finely adjust the power supply voltage of each power supply circuit X _i so that the peak value of the current becomes constant. As a result, according to the heat treatment apparatus of the embodiment of the present invention, it is possible to obtain a desired light intensity distribution and realize a desired temperature distribution for the substrate 1 to be processed having a large area. For example, the variation in the light intensity distribution and the temperature distribution can be suppressed to 5% or less with respect to the target substrate 1 having a large area of about 930 mm × 720 mm.

<Method for Manufacturing Semiconductor Device>
Next, a method for manufacturing a semiconductor device according to an embodiment of the present invention will be described by taking polycrystallization of an a-Si film as an example. Is not limited to:
(A) First, as shown in FIG. 7, for example, a transparent substrate 1a having a large area of about 930 mm × 720 mm is prepared. A specific example of the transparent substrate 1a is a glass substrate. A silicon nitride film (SiN _x film) 1b having a thickness of about 20 to 100 nm is formed on the upper surface of the transparent substrate (glass substrate) 1a, and a silicon oxide film (SiO _x having a thickness of about 50 to 150 nm is formed on the SiN _x film 1b. (Film) 1c is sequentially deposited by CVD or the like (specifically, the SiN _x film 1b is preferably a Si ₃ N ₄ film, and the SiO _x film 1c is preferably a SiO ₂ film, depending on the purpose) Does not necessarily have a stoichiometric composition). Furthermore, an a-Si film (semiconductor film to be processed) 1d having a thickness of about 20 to 100 nm is deposited on the SiO _x film 1c by a CVD method or the like to prepare a substrate 1 to be processed having a large area.

(B) Next, the substrate 1 to be processed is placed and fixed on the upper surface of the stage 21 shown in FIG. The longitudinal direction of the substrate 1 to be processed having a large area and the horizontal direction in which the stage 21 can move are made to coincide with each other and fixed to the stage 21. The stage 21 may be heated to increase the reactivity of the substrate 1 to be processed. Next, a processing gas such as an inert gas such as nitrogen (N ₂ ) gas, argon (Ar) gas, helium (He) gas, or a mixed gas of any of these inert gases and oxygen (O ₂ ). Is controlled from the gas introduction port 22 by a mass flow controller or the like, and the flow rate and partial pressure of the annealing atmosphere gas in the processing chamber 2 are adjusted while exhausting excess gas from the gas exhaust port 23. The atmosphere in the processing chamber 10 may be a vacuum. In the case of a vacuum, it is preferable to arrange a dummy glass plate directly under the window 24 to prevent clouding of the window due to Si deposition by heat treatment. The dummy glass plate should be replaced periodically.

(C) When a signal such as a pulse wave is emitted from the trigger circuit 33 in FIG. 6 in a state where the processing gas is flowed (or in a vacuum reduced pressure state), the signal is accumulated in each capacitor 66 of the plurality of power supply circuits X _i. The charged electric charge moves to the discharge part 32 of the corresponding rod-shaped lamp Q _i . As a result, each rod-shaped lamp Q _i generates ultraviolet light of the first output level, and the ultraviolet light of the first output level irradiates the a-Si film 1d as shown in FIG. Passes through the a-Si film 1d and reaches a plurality of detectors D _i1 , D _i2 ,..., D _im . That is, of the emission spectrum of the rod-shaped lamp Q _{i using} the substrate 1 as an optical filter, light mainly transmitted through the a-Si film 1d and mainly composed of infrared light is a plurality of detectors D _i1 and D _i2. , ..., and reaches the D _im, further, a-Si film 1d thermal energy due to being heated is plural simultaneously detectors D _i1, D _i2, ..., in D _im To reach.

(D) The plurality of detectors D _i1 , D _i2 ,..., D _im are due to the ultraviolet light of the first output level of the corresponding rod-shaped lamp Q _i and the a-Si film 1d being heated. Thermal energy is received through the substrate 1 to be processed and the pinholes H _i1 , H _i2 ,..., H _im shown in FIG. 2, respectively, and the first light intensity I _i1 , I _i2,.・ ・ Measure I _im . Each comparison calculator Y _i of the control circuit unit 4, the first light intensity I _i1 measured respectively, I _i2, · · · · ·, the average value I _i of I _im, the first light The average value I _{i of the} intensity is compared with a reference value in each comparison calculator Y _i . When the average intensity value I _p of the ultraviolet light of the first output level of the specific rod-shaped lamp Q _p is lower than the reference value, the voltage value of the DC power source 62 of the corresponding power circuit X _p is increased in a constant voltage step, increasing the output of the corresponding rod-shaped lamp Q _p. On the contrary, when the intensity average value I _q of the ultraviolet light from the specific rod-shaped lamp Q _q is higher than the reference value, the voltage value of the DC power supply 62 of the corresponding power supply circuit X _q is decreased by a constant voltage step to cope with it. The output of the rod lamp _Qq is decreased. In this way, the plurality of detectors D _i1, D _i2, · · · · ·, by feeding back the light intensity of ultraviolet light of the first output level measured by the D _im in the power circuits X _i, large A desired temperature distribution can be obtained over the entire surface of the substrate 1 to be processed. At this time, the power supply voltage of each power supply circuit X _i is adjusted so that the peak current value measured via the current probe B _i becomes constant. In this way, by adjusting the emission intensity distribution, the first output level ultraviolet light output from each of the rod-shaped lamps Q _i is irradiated to the a-Si film 1d, and the a-Si film 1d irradiated with the ultraviolet light. The hydrogen bonded to the dangling bond of a-Si is desorbed from.

(E) Further, the voltage controller shown in FIG. 5 in the state where the processing gas is flowed (or in the vacuum reduced pressure state), the second power supply voltage of each power supply circuit X _i is higher than the first output level. ultraviolet light output level is adjusted so as to be outputted from each of the rod-shaped lamp Q _i. At this time, it is preferable to switch the capacitor 66 shown in FIG. 6 so that the pulse has a shorter half-width than the first output level. For example, the pulse half width is preferably 1 ms or less, and more preferably 50 μs or less. When ultraviolet light of the second power level irradiates the a-Si film 1d, a portion passes through the a-Si film 1d, a plurality of detectors D _i1, D _i2, ·····, reaches D _im . The plurality of detectors D _i1 , D _i2 ,..., D _im emit the ultraviolet light at the second output level of the corresponding rod lamp Q _i and the pinholes H _i1 , H _i shown in FIG. _i2, · · · · ·, a second light intensity respectively received through the _{H im I i1, I i2,} ·····, measuring the I _im. Each comparison calculator Y _i of the control circuit unit 4, a second light intensity I _i1 measured respectively, I _i2, · · · · ·, the average value I _i of I _im, the second light The average value I _{i of the} intensity is compared with a reference value in each comparison calculator Y _i to adjust the light intensity of the ultraviolet light at the second output level of the rod-shaped lamp Q _i . In this way, a desired temperature distribution can be obtained over the entire surface of the substrate 1 having a large area. At this time, the power supply voltage of each power supply circuit X _i is adjusted so that the peak current value measured via the current probe B _i is constant, as in the case of the ultraviolet light of the first output level. . In this way, the emission intensity distribution of the ultraviolet light at the second output level is adjusted, the a-Si film 1d is irradiated, and the a-Si film 1d irradiated with the ultraviolet light is instantaneously melted and has a large area. The a-Si film 1d is polycrystallized.

According to the method of manufacturing a semiconductor device according to the embodiment of the present invention, a desired heat treatment temperature distribution can be realized for the large-area a-Si film 1d. Therefore, the a-Si film 1d having a large area can be uniformly polycrystallized in a short time. As a result, according to the method of manufacturing a semiconductor device according to the embodiment of the present invention, the polysilicon having a mobility of 10 to 500 cm ² / Vs and an average particle size of about 0.25 to 0.35 μm over the entire surface of a large area. Since a film can be obtained, a large area, high quality polysilicon film with high in-plane uniformity can be manufactured in a short time at a low cost. Furthermore, since a bar lamp that is less expensive than the discharge part of the excimer laser is used, the manufacturing cost of the semiconductor device can be reduced.

(Other embodiments)
As described above, the present invention has been described according to the above-described embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

For example, as shown in FIG. 9, the ultraviolet light intensity distribution at the second output level from the plurality of rod-shaped lamps Q _i varies depending on the distance from each rod-shaped lamp Q _i and how the lamp lights overlap. For this reason, unevenness occurs in the distribution of the light intensity I in the irradiated portion K. Therefore, in order to make the distribution of the light intensity I uniform, the stage lamp 42 shown in FIG. 5 is used to slide the stage 21 in the horizontal direction, and the corresponding bar lamps Q _i while overlapping the irradiation point positions. The second output level of ultraviolet light may be irradiated. Specifically, as shown in FIG. 12, after irradiating light from rod-shaped lamps Q _i corresponding to the regions α, β,..., The stage driving device 42 moves the stage 21 onto the substrate 1 to be processed. Slide in the longitudinal direction. Subsequently, as shown in FIG. 13, an overlap region αβ composed of half of the region α and half of the region β, an overlap region βγ composed of half of the region β and half of the region γ,. The ultraviolet light at the second output level of the corresponding bar lamp Q _i may be irradiated.

In FIG. 1, the case where the stage 21 is accommodated on the bottom surface of the processing chamber 2 inside the processing chamber 2 has been described. However, as shown in FIG. 9, the stage 21 may be configured to form a part of the processing chamber 2. In the heat treatment apparatus shown in FIG. 9, the rear windows W _ij (i = 1 to n, j = 1 to m; n and m are integers of 2 or more corresponding to the positions of the plurality of pinholes H _ij in FIG. .) Is fixed to maintain the confidentiality of the processing chamber 2 by O-ring or the like. In the case of heat treatment at atmospheric pressure, etc., confidentiality maintenance by O-ring or the like is not necessary. In FIG. 9, the rear window W at the position of the central axis of the plurality of rod-shaped lamps Q _i (i = 1 to n, n is an integer of 2 or more) disposed above the processing chamber 2 is parallel-projected. _A plurality of detectors D _ij (i = 1 to n, j = 1 to m; n and m are integers of 2 or more) are arranged via _ij , and the light intensity is measured by the plurality of detectors D _ij . It is possible. When the stage 21 is moved in the horizontal direction (left and right as viewed in the plane of FIG. 9), it is necessary to move integrally with the processing chamber 2, and the gas introduction port 22 and the gas exhaust port 23 include a bellows tube or a flexible pipe. What is necessary is just to connect with flexible piping, such as.

In the heat treatment apparatus described with reference to FIG. 1, heat treatment at almost normal pressure (atmospheric pressure) has been mainly described. However, the lamp heating treatment of the present invention is not limited to a simple heat treatment, and can be applied to a CVD furnace, an epitaxial growth furnace, or the like. In the case of a CVD furnace or an epitaxial growth furnace, a reactive source gas such as monosilane (SiH ₄ ), disilane (Si ₂ H ₆ ) or ammonia (NH ₃ ) is introduced together with a carrier gas from the gas introduction port 22 shown in FIG. Just do it. Further, a doping gas such as arsine (AsH ₃ ), phosphine (PH ₃₎ , diborane (B ₂ H ₆ ) or the like may be introduced from the gas introduction port 22. In particular, in the case of CVD or epitaxial growth that is heated by a rod-shaped lamp Q ₁ containing ultraviolet (UV) light, the surface energy reaction such as surface migration is promoted by ultraviolet energy. A semiconductor film or an insulating film can be deposited.

When applied to a CVD furnace or an epitaxial growth furnace, as shown in FIG. 10, a back window 24b is provided at the bottom of the processing chamber 2 to maintain confidentiality, and a plurality of detectors D _ij are provided via the back window 24b. (I = 1 to n, j = 1 to m; n and m are integers of 2 or more) may be configured to measure the light intensity. Also in the case of the structure of FIG. 10, if it is necessary to move the substrate 1 to be processed in the horizontal direction (left and right direction toward the paper surface of FIG. 9) during the heat treatment, it is necessary to move together with the processing chamber 2. The gas introduction port 22 and the gas exhaust port 23 may be connected by a flexible pipe such as a bellow tube or a flexible pipe. In the case of the structure of FIG. 10, since light enters through the back window 24b, the pinhole H _ij shown in FIG. 1 is not necessary. However, if it is necessary to limit the incident light due to the output of the rod-shaped lamp Q _i and the sensitivity of the detector D _ij , a separate pinhole may be inserted between the back window 24b and the detector D _ij .

Alternatively, as shown in FIG. 11, the processing chamber 2 is made of a transparent material as a whole, and a plurality of detectors D _ij (i = 1 to n, j = through the wall surface (back surface) of the processing chamber 2. 1 to m; n and m are integers of 2 or more.) May measure the light intensity. The transparent material constituting the processing chamber 2 is preferably a material transparent to ultraviolet (UV) light such as quartz glass or sapphire glass. In the heat treatment apparatus shown in FIG. 11, a part of the processing chamber 2 functions as a window having good ultraviolet transmittance characteristics. Also in the case of the structure of FIG. 11, if it is necessary to move the substrate 1 to be processed in the horizontal direction (left and right direction toward the paper surface of FIG. 9) during the heat treatment, it is necessary to move together with the processing chamber 2. The gas introduction port 22 and the gas exhaust port 23 may be connected by a flexible pipe such as a bellow tube or a flexible pipe. Also in the case of the structure of FIG. 11, light enters through the wall surface (back surface) of the processing chamber 2, so that the pinhole H _ij shown in FIG. 1 is not necessary. However, if it is necessary to limit the incident light due to the output of the rod-shaped lamp Q _i and the sensitivity of the detector D _ij , a separate pinhole may be inserted between the back window 24b and the detector D _ij . The structure shown in FIGS. 10 and 11 is not limited to a CVD furnace or an epitaxial growth furnace, but can be applied to various heat treatment furnaces such as an oxidation furnace and a diffusion furnace. In FIG. 11, a flange 25 is provided on the right side surface of the processing chamber 2 to maintain the confidentiality of the processing chamber 2 and the processing chamber 2. 1, 9, and 10, the port for loading and unloading the substrate 1 to be processed is omitted, but it is needless to say that various ports for loading and unloading can be used depending on the purpose of the heat treatment such as the flange structure shown in FIG. 11. .

The processing pressure is not limited to atmospheric pressure, for example, a vacuum pump is connected to the gas exhaust port 23, and the processing chamber 2 is slightly depressurized slightly below atmospheric pressure to about ⁵ Pa, or about 10 ⁻³ Pa to 10 ⁻⁵ Pa. Of course, the pressure may be reduced. As the vacuum pump, a dry pump, a mechanical booster pump, a turbo molecular pump, a cryopump, or the like can be used.

  As described above, the present invention naturally includes various embodiments and modifications not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

1 is a schematic cross-sectional view schematically illustrating a heat treatment apparatus according to an embodiment of the present invention. It is a schematic plan view explaining the positional relationship between the stage shown in FIG. 1, a pinhole, a detector, and a corresponding bar lamp. It is a graph which shows the emission spectrum of the light irradiated from the rod-shaped lamp used for the heat processing apparatus which concerns on embodiment of this invention. It is a graph which shows the relationship between the enclosed amount of mercury contained in a rod-shaped lamp, and the emitted light amount of a rod-shaped lamp. It is a block diagram which shows the structure of the control circuit part of a rod-shaped lamp. It is a circuit diagram which shows the detailed structure of the discharge circuit shown in FIG. It is typical sectional drawing which shows the optical path which the ultraviolet light from a rod-shaped lamp irradiates a to-be-processed substrate. It is a graph which shows distribution of the ultraviolet light intensity in the heat processing apparatus which concerns on embodiment of this invention. FIG. 5 is a schematic cross-sectional view schematically illustrating a heat treatment apparatus according to another embodiment of the present invention. FIG. 5 is a schematic cross-sectional view schematically illustrating a heat treatment apparatus according to another embodiment. FIG. 5 is a schematic cross-sectional view schematically illustrating a heat treatment apparatus according to another embodiment. It is a top view explaining the irradiation area | region of each bar lamp with respect to a to-be-processed substrate. It is a top view explaining the case where a to-be-processed substrate is moved and the irradiation area | region of each rod-shaped lamp with respect to a to-be-processed substrate is made to overlap.

Explanation of symbols

1 ... target substrate 1a ... target substrate 1b ... SiN _X film 1c ... SiO _X film 1d ... amorphous semiconductor (a-Si, the processed semiconductor film) film 2 ... processing chamber 4 ... control circuit 21 ... Stage 22 ... Gas introduction port 23 ... Gas exhaust port 24 ... Window 24b ... Back window 25 ... Flange 31a, 31b, 61a, 61b, 61c, 61d ... Terminal 32 ... Discharge unit 33 ... Trigger circuit 41 ... CPU 42 ... Stage drive device 43 ... Each Comparator 44 ... Current measuring device 45 ... Voltage controller 62 ... DC power supply 63 ... Power switch 64 ... Inverted L-type circuit 65 ... Diode 66 ... Capacitor 100 ... Display device α, β, γ ... Region αβ, βγ ... Overlap region B _{i (i} = 1~n) ... current probe _{D ij (i = 1~n, j} = 1~m) ... detector I ... light intensity K ... irradiated portion P _1, P ₂ ... node H _ij (i = 1-n, j = 1-m) ... pinhole M _i (i = 1-n) ... reflecting mirror Q _i (i = ₁ -n) ... bar-shaped lamps R ₁ , R ₂ ... resistance V _SS : Ground potential X _i (i = 1 to n): Each power supply circuit W _ij (i = 1 to n, j = 1 to m): Rear window

Claims (14)

A processing chamber having a window portion having a good ultraviolet-transmitting property and containing a substrate to be processed;
A plurality of rod-shaped lamps arranged at the same pitch in a fixed direction outside the processing chamber and heating the substrate to be processed with light of an emission spectrum including ultraviolet rays through the window portion;
A plurality of detectors arranged to face the array of the plurality of rod-shaped lamps so as to receive light of the plurality of rod-shaped lamps independently through the substrate to be processed;
And a control circuit unit that independently and simultaneously controls the outputs of the plurality of rod-shaped lamps based on the distribution of the light intensity measured by the plurality of detectors. Each of the plurality of rod-shaped lamps emit light having a spectrum in which the wavelength integrated value of the light intensity in the wavelength region of wavelength 400 nm or less is 20% or more with respect to the wavelength integrated value of the light intensity in the wavelength region of wavelength 400 nm or more. The heat treatment apparatus according to claim 1, which emits light. 3. The heat treatment apparatus according to claim 1, wherein the plurality of detectors are arranged on a single rod-shaped lamp along the axial direction of the plurality of rod-shaped lamps. . 4. The heat treatment apparatus according to claim 1, wherein each of the plurality of detectors receives light from the plurality of rod-shaped lamps via a pinhole. 5. The control circuit unit further includes a current measuring device for measuring a peak value of a current waveform supplied to the plurality of rod-shaped lamps, and a power supply voltage of a power supply circuit to the plurality of rod-shaped lamps is determined by the peak value. The heat treatment apparatus according to claim 1, wherein each of the heat treatment apparatuses is controlled independently. Placing the substrate to be processed inside the processing chamber;
Light having an emission spectrum including ultraviolet rays from a plurality of rod-shaped lamps arranged at the same pitch in a fixed direction outside the processing chamber through a window portion having a good ultraviolet transmission property provided in a part of the processing chamber. And heating the substrate to be processed;
Independently measuring the light intensity of the light of the plurality of rod-shaped lamps via the substrate to be processed;
And a step of independently and simultaneously controlling the outputs of the plurality of bar lamps based on the measured light intensity. Each of the plurality of rod-shaped lamps emit light having a spectrum in which the wavelength integrated value of the light intensity in the wavelength region of wavelength 400 nm or less is 20% or more with respect to the wavelength integrated value of the light intensity in the wavelength region of wavelength 400 nm or more. The heat treatment method according to claim 6, which emits light. 8. The heat treatment method according to claim 6, wherein the light intensity is measured at a plurality of locations on a single rod lamp along the axial direction of the plurality of rod lamps. 9. Measuring a peak value of a current waveform supplied to the plurality of rod-shaped lamps;
9. The heat treatment method according to claim 6, further comprising: independently and simultaneously controlling power supply voltages of a power supply circuit to the plurality of rod-shaped lamps independently and simultaneously according to the peak value. . A step of installing a substrate to be processed having a semiconductor thin film formed on at least a surface thereof; and a plurality of rod-shaped lamps arranged at a fixed pitch in a fixed direction at a position facing the semiconductor thin film formed on the substrate to be processed. Introducing light of an emission spectrum including ultraviolet light into the thin film, and heating the substrate to be processed;
Independently measuring the light intensity of the light of the plurality of rod-shaped lamps via the substrate to be processed;
Independently controlling the outputs of the plurality of rod-shaped lamps based on the measured light intensity, and processing at least a part of the semiconductor thin film or providing a new film on the surface of the semiconductor thin film A method for manufacturing a semiconductor device, comprising: forming a semiconductor device. Each of the plurality of rod-shaped lamps emit light having a spectrum in which the wavelength integrated value of the light intensity in the wavelength region of wavelength 400 nm or less is 20% or more with respect to the wavelength integrated value of the light intensity in the wavelength region of wavelength 400 nm or more. The method of manufacturing a semiconductor device according to claim 10, wherein the semiconductor device emits light. The semiconductor device according to claim 10 or 11, wherein the light intensity is measured at a plurality of locations on a single rod-shaped lamp along the axial direction of the plurality of the rod-shaped lamps. Method. Measuring a peak value of a current waveform supplied to the plurality of rod-shaped lamps;
13. The semiconductor device according to claim 10, further comprising: independently controlling a power supply voltage of a power supply circuit to the plurality of rod-shaped lamps according to the peak value. Production method. The semiconductor device according to claim 10, wherein the semiconductor thin film is an amorphous semiconductor, and the amorphous semiconductor becomes a polycrystalline semiconductor by heat treatment by introducing light. Method.

Images